Search for Permanent Electric Dipole Moments of Francium Atom

Yasuhiro SAKEMI Research Center for Nuclear Physics (RCNP), Osaka University

For EDM collaboration at RCNP

K.Hatanaka, A.Tamii, S.Morinobu, Y.Shimizu, K.Fujita, Y.Tameshige, H.Matsubara,T.Kaneda (RCNP)K.Imai, Y.Takahashi, T.Murakami (Kyoto Univ.)

T.Wakasa (Kyushu Univ.), Bhanau P. Das (Indian Institute of Astrophysics)

Physics motivation

EDM experiment

Present status of Fr EDM search at RCNP

Summary

Electron EDM search

Francium atom

Fundamental interaction

Search for permanent EDM

CPT ~ invariant in quantum field theory : No evidence of violationT: Time Reversal ~ No evidence of violation CP: violation was found ~ K0, B decayCPT theorem + CP violation → T violation ?

Window to look at Beyond the Standard Model ~ Supersymmetry …

Time Reversal Symmetry ~ Violation ? ~ Test !

+-

+-

Td

s

EDM and MSSM

2

sin~

Mµθ

Electron EDM in MSSM → limit to SUSY particle mass and CP-violating phase

M=500 GeV case

Phase pattern ~ limit the SUSY particle mass

Dominant diagram

dn=Δu・du+Δd・dd+Δs・ds

Origin of EDMsT

heor

y

Experiments H

igh

ener

gy

Nuc

lear

A

tom

ic

Fundamental model ~ Supersymmetry, ….

QuarkEDM

QCD

Nucleonn

dn=Δu・du+Δd・dd+Δs・ds

Nuclear Atomic

QCD

Atomic theory

Nuclear theory

DiamagneticAtoms

Hg,Xe,Rn

Schiff Mom.

Z2(RN/RA)3

Molecular

Atomic theory

MoleculesPbO,YbF,TlF

Emol

Atomic theory

ParamagneticAtoms

Tl,Ce,FrZ3α2

QuarkChromo-EDM

ElectronEDM

Electric Dipole Moment

de(Standard Model)<10-37

Status of EDM experiments

Current limit e-EDM : |de|<1.5×10-27

from E.D.Commins ,205Tl

A challenge is set ! de < 10-28 e・cm

if EDM is observed~ Beyond the Standard Model

if EDM is measured~ signal of supersymmetry …~ mechanism of SUSY violation

Particle

Exp. Limit [10-27 e cm]

SM [factor to go]

Possible New Physics [factor to go]

e (Tl) < 1.6 1011 ≤ 1 µ < 1.05 *109 108 ≤ 200 τ < 3.1 * 1011 107 ≤ 1700 n < 63 104 ≤ 60 Tl (odd p) < 105 107 ≤ 105 Hg (odd n) < 0.21 105 various

EDM limits

EDM Measurement and Sensitivity

TNEKehd

⋅⋅⋅⋅⋅=

τδ 111

2

EdhEdBhEdBh

⋅=∆⇒

⋅−⋅=

⋅+⋅=

↑↓

↑↑

42222

νµνµν

E E

Sensitivity :

K: Enhancement factor ~ Atom EDM = Largest ~ FranciumE : Electric Field ~ Strong, 100 kV/cm = Laser trap in high vacuumN : Number of Particles ~ Many particles ! = Ion Source + Atom coolingτ: Coherence Time (Stored time) ~ Long ! = Laser trapT : Lifetime of Experimentalist ~ Long !

Electric dipole moment : d

System containing EDM

K×de

Amplified !

20

252

23

)0(~

~~

aeVZ

Zd

dK

s

e

atom

αψ

α

Why Francium traps ?

Heavy atoms amplify EDM ~ P.G.H. Sandars, Oxford, 1960sEnhancement factor:

Enhancement factor

0

200

400

600

800

1000

1200

1400

0 20 40 60 80 100

K

Char

ge :

Z

Enhancement factor simple

RbXe Cs

Tl

FrE

nhan

cem

ent f

acto

r

Heaviest Alkali metal ~ Francium : ⇒simple electronic structure and large nucleus ⇒Enhancement of EDM ~ largest ! : 210Fr ~ K=1150

Several isotopes with long lifetime > 1 min. ⇒210Fr =3.2 min., 212Fr =19.3 min.

No stable isotopes, but traps compensate scarcity Magneto-Optical Trap (MOT) : localize the trapped atoms

⇒systematic error reduced Temperature of MOT cloud < mK ~ Doppler-free spectroscopy

Presented by Dr.Giulio Stancari @ INFN Ferrara at ISOLDE workshop at CERN, Feb.2006

Fr from the decay of 225Ac

EDM search in the world

MOT+Laser Trap

MOT+Laser Trap

Atomic beamMOTMOT/PenningMOTTrap

171Yb (p) KyotoXe (p)Tokyo Tech.

TISOLTRIUMF~10-27Best limit 205Tl (e)California / LBL

~10-28This proposal210-212FrRCNP

First beam Ra (p)TRIuPKVIAtomic structure210FrSUNY

Goal Status Elements ProjectInstitute

Dy,Sm,BaFr

Yb

205TlRa

129Xe 3P2

Others199HgRn129Xe 1S0Nucleus OthersFe3+CsRbElectron

Elements EDM

ExperimentFrancium Production with Heavy Ion Fusion Reaction :

197Au(18O,xn)209-211Fr

18O beam from AVF cyclotron

Au targetY neutralizer Trapped Francium

Laser Beam

Fr+ ion

Surface Ionizer

EDM search

High intensity ECR ion source

Nuclear Physics

Magneto-Optical Trap

Atomic Physics Particle Physics

TRV SUSY…

Fundamental interaction

Super Conducting ECR Heavy Ion SourceLaser Trap

Apparatus

Ring CyclotronNew Beam Line for Fr Production

New Beam LineLaser Trap

Overview at RCNP

AVF Cyclotron

Ring Cyclotron

ECR ion source

Planned layout of beam line

Primary beam

SC ECR ion source

6 pμA1.1 pμ A

Beam intensity (expected)

~ 100 MeV 18O6+ beam from AVF cyclotronNew ion source : 18GHz Superconducting ECR

For heavy ion and polarized 6Li beam Construction ~ completed soonOperation test ~ will be done next weekMaximum intensity

~ radiation protection limit: 6 puA

Extracted beam

To AVF

Francium production

Fusion Reaction :18/16O + 197Au → 207-211Fr + Xn

Francium desorbs from the target surface as atoms/ions according to

−

=+

kTEE

nn IPWFexp

21

0

18O beam from AVF

Au target Y targetFr+ ion

Fr atom

To Trap/Cooling

Surface ionizer Neutralizer

18O+197Au Fr production

0.01

0.1

1

10

100

1000

50 70 90 110 130

beam energy (MeV)

Cro

ss s

ecti

on (

mb)

212Fr 211Fr 210Fr 209Fr 208Fr

18O+197Au

19F+198Pt Fr production

0.01

0.1

1

10

100

1000

50 70 90 110 130

Beam Energy

Cro

ss S

ection (

mB

)

212Fr 211Fr 210Fr

19F+198Pt

Target : Gold (Au) ~ EWF(5.1eV)>EIP(4.1eV) → Fr+ ionTarget : Yttrium (Y) ~ EWF(3.1eV)<EIP(4.1eV) → Fr atom

210Fr

212Fr

18O+197Au

Fr

Rn

At

Po

Bi

209 210 211

206 207 208

209 210

207 208

204 205 206

Ionization Potential

(eV)

3.83

10.748

9.65

8.43

7.289

Focal Plane for beam diagnosis

New beam line

Focal Plane

Dispersive Transport Achromatic Transport

Vertical Vertical Horizontal Horizontal

Beam size <120mm

Beam energy resolution Beam emittance &Beam transport

Function as spectrometer

Surface Ionizer

Fr+ ion to Magneto-Optical Trap

Primary beam

18O beam from AVF1 4 7

10

13

16

19

22

25

28

31 n

1

10

100

1000

10000

event(arb. unit)

energy (MeV)

particle

emitted particles

n p alpha gamma

Neutron ~ a few MeV⇒ damage to detector (CCD etc..)⇒ MOT should be located

far from production target

New Beam Line for EDM search experiment

For EDM CollaborationK.Hatanaka, A.Tamii, S.Morinobu, Y.Shimizu, K.Fujita, Y.Tameshige, H.Matsubara,T.Kaneda (RCNP)

K.Imai, Y.Takahashi, T.Murakami (Kyoto Univ.)T.Wakasa (Kyushu Univ.), Bhanau P. Das (Indian Institute of Astrophysics)

Surface ionizer will be set here

Beam transport and diagnosis with new beam line

Beam ~ 2 components

Phase slit adjustments ~ 1 component ~ higher transmission

Before AVF tuning Construction ~ completed Transport test with 18O beam ~ completed Beam diagnosis ~ routinely used for high resolution beam preparationTransmission ~ more than 90 % ~ depend on beam emittance

After AVF tuning

AVF accelerator turn ~ separation good

Surface ionizer

197Au disk on W support rod 1200 K for surface ionizer 3 kV to extract Fr+ ion Fusion reaction : 197Au(18O,xn)215-xFrFocusing elements ~ design with 3d field calculation

Design ~ almost finished Construction ~ will be completed in this summer 30 mg/cm2

Fr production

100 mg/cm2 ~50 um

18O Beam

Based on Surface ionizer at SUNY

Au (just below the melting point)

W(Tungsten rod)

Design : Surface ionizer

+ Focus elements

Extracted Fr beam

Francium ion transport

Fr production target •Focus point •Beam size tuning ~ possible •Surface ionizer locate

Laser Trap

Concrete shield Fr+ ion beam Electrostatic lenses

Einzel lens + electrostatic Q lens

NeutralizerOven (Y) temperature : 1000 K ~ heater temperature for Fr atom releaseCapturing velocity of MOT : Vc~1 m/sFraction of trapping atoms : 10-4 ~ 10-5

High trapping efficiency realization ~ need to cool atoms

Velocity distribution

0

0.0005

0.001

0.0015

0.002

0.0025

0.003

0.0035

0 100 200 300 400 500 600 700 800

Atom velocity (m/s)

frac

tion

210Fr@T=1000K 85Rb@T=568K

vFr~281 m/s, vrms~345 m/s

vRb~333 m/s , vrms~408 m/s

Heater

Material surface

LED

Fr ion

Fr atom

Laser cooling and trapping

Goal : Temperature ~ μK

Fr atom beam

Transverse coolingEDM proving region

Magneto-OpticalTrap (MOT)

Decelerating laser

Optical Dipole TrapFiber Laser used

Buffer gas cooling

Laser cooling

Trap Chamber

Science Chamber

Trap view

Trap: 718nm Repump: 817nm

F=11/2

F=13/2

F=9/2

F=11/2F=13/2F=15/2

46.8 GHz

397 MHz500 MHz

617 MHz

7s2S1/2

7p2P3/2

Trap laser : 718 nm and 817 nmExternal Cavity LD (ECLD) + Taper amplifierFabrication ~ in progress

Beam diameter ~ 30 mmAnti-helmholz coil ~ 10 G/cm Pyrex cell with dryfilm coatingDecouple MOT from target area (radiation and vacuum)Laser for Optical Dipole trap : red detuned

High power fiber laser used

ECLD+Taper amp.

ECLDTaper amp.

~ 1W

MOPA configuration : Master oscillator ~ ECLD ~ 10 mWPower amplifier ~ Taper amp. ~ 1 W

Low cost Compact

LD

Grating What should be solved !~ 718 nm Taper amp …

ECLD

MOT Anti-Helmholz coil

Trap Cell

σ+ σ-

Magnetic field gradient~ 5 G/cm

σ+σ- σ-σ+M=-1, 0, 1 M=-1, 0, 1

10 cm

Cooling atoms

( )( )[ ]

Laser

cvbounces

cvDnLasercMOTDntrap

vPfN

vPfvPP εεηεεη ⋅−

−−

⋅⋅=⋅⋅⋅=

1

1

1111

)(Goal : Cooled atom number ~ 108 → Trap efficiency : Ptrap~ higher !

ηn Neutralizer efficiency : material, LEDεD Decelerator efficiency : Collimation laserPMOT MOT efficiency : Decelerator

fv trap size : Laser sizeP1 trap efficiency : Laser detuning, powerNbounce Bounce : Coating, LED

εLaser Laser trap efficiency : Laser power

Efficiency with Decelerator

0

0.2

0.4

0.6

0.8

1

1.2

star

t

Neutra

lizer

Decele

rato

r

MOT

Trap Cell

Bounc

e

Lase

r Tra

p

Cooling/Trapping item

Eff

icie

ncy

Efficiency Total efficiency

Efficiency w/o Decelerator

0

0.2

0.4

0.6

0.8

1

1.2

star

tNeu

traliz

erDec

elera

tor

MOT Tra

p

Cell

Bounc

e

Lase

r Tra

p

Cooling/Trapping item

Eff

icie

nc

y

Efficiency Total efficiency

Buffer gas cooling

Cooled Fr distribution

-0.2

0

0.2

0.4

0.6

0.8

1

1.2

0 2 4 6 8 10 12 14 16 18 20

Velocity (m/s)

fra

cti

on

Fr@0.01m/s Fr@0.1m/s Fr@1m/sCapturing velocity ~ 1 m/s

0.66

0.040.001

Velocity distribution

0

0.02

0.04

0.06

0.08

0.1

0 100 200 300 400Velocity

Fra

ctio

n

Fr@1000K Fr@1K Fr@0.1K Fr@0.01K

Buffer gas cooling ~ J.M.Doyle@HarvardApparatus delivered from HarvardStarted to check the feasibility at Kyoto

LHe bath at 5 K

LN2 bath at 77 K

BufferGas (He)

Cell

Ablation YAG

Atomic beam

Cooling

He

EDM measurement

Ramsey’s method of Separated Oscillatory Fields ~ Atomic beam

Larmor frequency determination by Faraday Rotation measurement~ Trapped atom

Ramsey’s method ElectronElectron

LaserRF B-field

RF B-fieldLaser

tEdF

tEdF

a

a

⋅⋅−∝

⋅⋅+∝

−

+

2121

Faraday rotation measurement

Linier polarization Medium

Faraday Rotation angle : φB

Optical Pumping Laser ~ Atom polarized

Spin precession : ω

Prove laser

( ) ( )θωτφ +⋅−⋅Ψ= TT sinexp

E

Eda ⋅⋅=∆⋅ 4ωh

Fr EDM search timeline accyracy

1.0E-29

1.0E-28

1.0E-27

1.0E-26

1.0E-25

0 5 10 15 20 25 30 35

measurement time (days)

ED

M a

ccura

ct

(e c

m)

210Fr 210Fr+high extraction210Fr+high intensity 212Fr212Fr+high extraction 212Fr+high intensity

SUSYLarge CP phase

SUSYSmall CP phase

Current limit ~ 205Tl 5yeras data

SUNY

Phase1 ~surface ionizer

Phase2 ~ion source

Phase3 ~MOT

2007/LHC start2009/LHC high luminosity

Goal

2005

2006

2007

2008

2009

•Proposed at RCNP•Beam line constructed•ECR ion source•Surface ionizer •MOT ~ ready•Fr production test•Atom cooling test•Shakedown everything•Fr trap optimization •Test experiment (Phase1)•Data taking •Phase2,Phase3….

To achieve de < 10-28 e・cmHigh intensity beam : 6 puA⇒SC ECR ion source Trapped atom ~ increased : 108

⇒MOT with Cooling

EDM in Japan

CPT Models Particle Hadron Nuclear Atom RCNP

J-PARC RIKENProf.Asahi-san’s group : Xe…

Other radioactive atoms..

KM

Higgs

SUSY

LR, Strong CP…

de

dq

dqC

dn

dpara

ddiaQschiff

One may miss something essential by focusing on ONE EDM only!

Next step

15N+205Ta→213Ra+7n

Next species

Nuclear EDM with diamagnetic atoms at RIBF@RIKEN High intensity heavy ion beam ~ 15N5+ : 50 MeV/uMany experts on atomic physics, quantum optics, …Magnetic separator, RFQ decelerator …

Detailed study should be done, But interesting ..

Summary Permanent EDM search

To find Physics beyond standard model, Supersymmetry, …Offer a nice way to approach new physics at low energy

EDM search at RCNP ~ development in progressIn the mean time: experimental apparatus preparation ECR ion source, beam line, surface ionizer, buffered gas cooling, MOT …Test experiment ~ should be ready in 2007..

We need NOT one EDM experiment, BUT MANY experiments needed !

Electron EDM : Paramagnetic atom ~ Fr at RCNP

Nucleus EDM : Diamagnetic atom ~ Xe and extend heavy radioactive atoms at RIBF

Lepton Flavor Violation (LFV) planned at PRISM(@J-PARC…)

New approach promise the significant progress to new physics. Let’s just do it together ! Thank you.

CPe

eUeBrd ϕγµ

⋅××→

− 1.0102.1)(~ 3

11: EDM and LFV ~ correlation